Apparatus for distilling solid carbonizable materials



Dec. 16, 1930. F. T. SNYDER 1,785,565

APPARATUS FOR DISTILLING' SOLID CARBONIZABLE MATERIALS Filed June 8, 1925 Patented Dec. 16, 1930 PATENT OFFICE FREDERICK T. SNYDER, OF NEW CANAAN, CONNECTICUT APPARATUS FOR DISTILLING SOLID CARBONIZAIBLE MATERIALS Application filed June 8, 1925, Serial Ito-35,806, and in. Canada May 14, 1925..

This invention relates broadly to'improvements in apparatus for the treatment of coal, oil shale, peat, garbage, bark, sawdust, or other material for the extraction of 'volatile constituents therefrom or for the formation of carbonized solid products suitable for use as fuel, and relates more -particularly to apparatus suitable for carrying out the processes disclosed in my copending applications executed of even date herewith, and filed under Serial Numbers 35,802 and 35,804, the 8th day of June, 1925.

An object of the invention is to provide apparatus of a type suitable for low temperature distillation of the material treated with an accompanying circulation through the material under treatment of a large volume of gas, whereby the volatile constituents may be extracted at temperatures below their vaporizing temperatures under atmospheric conditions with large yield'of gas, oils and other products, as may be desired.

Another object is to provide apparatus suitable for carbonizing material and producing therefrom a solid product of mechanical strength, thermal efficiency and other characteristics comparable with anthracite coal,

by fixing carbon on such carbonized material,

Still another object is to provide apparatus suitable for the cracking or decomposition of heavy hydrocarbon oils for the production of lighter and more valuable oils and for the production of gas.

A still further object is to provide an apparatus capable of regulation to accomplish the foregoing and other desirable objects, either separately or in such combination as may be desired. Additional objects and advantages may be ascertained from the following description and diagrammatic illustration, of one embodiment of the invention.

The apparatus comprises essentially a dis-- tillation chamber in which material may be heated, a fractional condensing apparatus,

means for producing the heat necessary for the operation of the apparatus and means for circulating gas through the retort and con- (lensing apparatus,

In the accompanying drawing, which diagrammatically illustrates one form of a paratus embodyingthe invention, but to t e precise details of which the invention is not confined, 11 designates a distillation chamber, preferably of the stack type shown,with which is associated a first stage condenser or heat exchanger 12, a second stage condenser 13, a stove 14 and a gas circulating device or exhauster 15.

The distillation chamber comprises a gastight shell 16 lined with refractory material 17. At the upper end of the distillation chamber is a feed charger 18 arranged to prevent the escape of gas during the introduction of material to be treated. At the lower end of the distillation chamber is a hopper bottom casing 19 open at the bottom but otherwise gas-tight and having gas-tight connection with the shell of the distillation chamber. The casing may be outwardly flanged around the bottom opening, as at 20, or otherwise suitably constructed. During operation of the apparatus, the bottom opening of the casing is closed by a car 21 or other conveying device, which makes a substantially gas-tight connection with the flange or other part of the casing except, possibly, when a full car is being replaced by an empty car. If desired, closure means may be provided to prevent entrance of air into the casing and kiln during change of cars. Within the casing and suitably spaced beneath the distillation chamber is a charge supporting plate 22, from which material is gradually removed by plows 23 mounted on a rotating ring 24, the material thus removed being directed by the .hop er bottom of the easing into the car 21 or ot er conve ver. The distillation chamber is supported in any suitable manner, for example, on legs 25. The interior of the distillation chamber comprises three zones, which may be identified as the upper or evaporating zone 26, the intermediate or carbonizin zone 27 and the lower or cooling zone 28. gas and vapor conduit 29 leads from the top of the distillation chamber into the first stage condenser or heat exchanger 12 and communicates with one end of the tubes 30 of the exchanger. A second conduit 31 leads from the opposite end of the tubes 30 to one end of the.

tubes :34 of the second stage condenser. A third conduit 33, which includes the exhauster 15, leads from the opposite end of the tubes 32 into the shell of the exchanger 12 outside the tubes. From this conduit a valved gas discharge main 34 leads out between the The first of these branches, 36, leads into the casing beneath the plate and is open for discharge of gas, or in any other suitable man ner communicates with the bottom of the distillation chamber. The second branch, 37, leads into thedistillation chamber between the lower and intermediate zones, the usual bustle pipe and tuyeres (not shown) being preferably employed to distribute entering gas uniformly around the charge in the distillation chamber. The stove 14 is inserted in this branch in such manner that the gas flows around the tubes 39 of the stove and is thereby heated. The stove may be supplied with gas fuel through a valved pipe 40 from any suitable source, such as the branch 36, but may be equipped to burn solid fuel. If desired, the flue 41 of the stove may be connected to the branch 37. The third branch, 38, leads into the distillation chamber between intermediate and top zones, the usual bustle pipe and tuyeres (not shown) being preferably employed to distribute the entering gas uniformly around the charge in the kiln. The condenser is cooled by water entering cold through. the pipe 42 and leaving hot through the pipe 43. Condensates in the exchanger and condenser are collected in the chambers 44 and 45 respectively and may be removed as necessary through valved pipes 46 and 47 respectively.

A pipe 48 leads into the distillation chamber between the bottom and intermediate zones and is supplied with air by a blower 49, preferably mechanically connected. with the exhauster, as indicated at 50, so as to operate in predetermined relation to the exhauster. The pipe 46 draining oily condensate from the exchanger leads into the distillation chamber between the bottom and intermediate zones, conveniently by way of the air pipe 48, and flow of oil is assured by a' pump 51. Oil from an outside source may be delivered into the pipe 46 through a valved. pipe 52 and, if desired, oily' condensate in the exchanger chamber 44 may be drawn off through a valved pipe 53 coincidentl'y with the supplying of oil from'an external source.

The stove may be dispensed with when sufand a hot gas from an external source passed into the distillation chamber by means of a connection 54 leading into the branch 37 The operation of the apparatus is as follows Material to be treated passes into the top of the distillation chamber through the charger 18 and works down through the three zones of the distillation chamber to the bottom, where it is ploughed off the plate 22 and falls through the hopper bottom casing into the car 21. Gas delivered through the branch 36 rises through the solid material in the lower zone of the kiln and is thereby heated, at the same time cooling the material below a temperature at which it will ignite upon exposure to air. This warmed gas rises through material in the intermediate or carbonizing zone and aids in heating the material to the required temperature. The gas rising from the cooling zone minglcs with hot gas entering through the branch 37, and the volume of gas thus increased so lowers the partial pressures of the volatiles in the material that these volatiles will evaporate at a temperature well below the fusing temperature of the material. The hot gas serves to heat the material to drive off high boiling volatiles and to partially crack the material with production of permanent gas. The hot circulating gas, and the gas and vapor distilled from the coal and rising from the carbonizing zone, are diluted and cooled by a large volume of cool gas entering through the branch 38, and serve to warm the material and distil off low boiling volatiles. This total volume of gas is so large relatively to the volume of vapor which can be evaporated from the material in the upper zone that the partial pressures of the volatiles in the material are sufficiently lowered to enable the volatiles to be distilled off at temperatures below their melting points and well below the melting point of the material when containing or when in presence of such volatiles. .The result is that a very complete evaporation can be effected without danger of fusing the material and without any sticking of the material.

The hot gas entering through the branch 37 may be. a part of the gas from the conduit 35 heated by passage through the stove, to which may or may not be added the hot products of combustion from the stove, depending on the product to be made and the amount of heat to be supplied. Alternatively, the

hot gas may be drawn from an external 48 to burn a portion of the materiahin which case thestove need not be used.

The total volume of gas and vapors leaves the distillation chamber through the conduit 29 leading to the heat exchanger, where the gas and vapors are cooled and give up heat to gas returning to the distillation chamber through the conduit 35. In the cooling process, high boiling 'oils condense and accumulate in the chamber 44. The gas and remaining vapors then pass to the condenser where most of the remaining vapors condense and are collected in the chamber 45. The cooled gas goes back to the heat exchanger to pick up heat previously given out.

'An amount of gas equal to that produced in the apparatus is withdrawn through the gas discharge main 34, so that .the amount of gas circulating in the system remains substantially constant. While only one condenser 13 has been shown, it will be understood that additional condensers operating at successively lower temperatures may be employed to fraction the condensate. Any usual or suitable scrubbing or washing ap paratus may be associated with the apparatus to remove any low-boiling oil which may pass the condenser and also a. 1y ammonia. If such apparatus is used, it may be inserted between the condenser and exhauster or at any other suitable point.

s The heavy high-boiling oils recovered in the heat exchanger 12 may be delivered into the distillation chamber at the bottom of the carbonizing zone and will be vaporized in the upwardly moving current of hot gas rising both from the cooling zone below and from.

the conduit 37. This oil vapor is brought into I contact with the hot carbonaceous material in the carbonizing zone which, during the proper operation of the distillation chamber, Is

at sufliciently hightemperature to effect a cracking of the oil vapors. The carbonac'eous materialbeing in the proper operation of the distillation chamber at higher temperature than the gas in contact with it, the vapor will crack on the carbonaceous material rather than in the gas stream, with the result that vapors of lighter oilsare liberated,

which'can be collected in the condenser 13 and, at the same time, the resulting carbon is deposited on the carbonaceous material assing down through the distillation chamer. If desired, oil from an outside source may be supplied through the pipes 52 and 46 and crackedin the distillation chamber, while the condensate recovered in the heat exchanger 12 may be simultaneously drawn 01f but retains the same sha e and size of parficlles or lumps that it ha when fed into the 1 11. equal to the weight of volatiles extracted, against which may be offset the added weight resulting from deposition of carbon. The material in process of distillation assumes a rim'ose conditionvbut not to such an extent as to render the particles or lumps fragile. When oil is cracked in contact with the hot rimose material, the carbon deposited from the oil fills the fissures of the rimose material and so strengthens the same that, when discharged from the apparatus, it has mechani cal strength equal to or greater than the strength of the material prior to treatment. In this strengthening operation, the amount of carbon added by deposition may be less than equal to or greater than the amount of carbon removed by distillation, so that it is possible to produce fuel of substantially the same heat value as the original material.

Having thus described my invention, what I claim is 2- 1. In apparatus for distilling carbonaceous material, a vertical distillation chamber including an upper evaporating section, an intermediate carbonizing section and a bottom cooling section, a conduit leading to the bottom of thecooling section to supply cooling gas, a second conduit leading to the bottom of the carbonizing section to supply hotter gas, and a third conduit leading to the bottom of the evaporating section to supply cool gas thereto, and a fourth conduit leadingfrom the top of the distillation chamber for Withdrawing all the gas supplied by the other conduits, a heat exchanger into which the fourth conduit discharges, a condenser connected to the heat exchanger to receive gas therefrom, a reflux connection between the condenser and heat exchanger to deliver cooled gas from the condenser to the exchanger for reheating, connections between the heat exchanger and the first, second and third conduits for supplying reheated gas thereto.

2. In combination with a device according to claim 1, a pipe leading from the base of the heat exchanger into the distillation chamber at the bottom of the carbonizing section, and a pump connected in said pipe to transfer condensate into the distillation chamber.

3. In combination with a device according to claim 1, an exhauster in the connection between the heatexchanger and condenser to circulate gas in the system, and avalved outlet in the'connection between the exhauster and the heat exchanger.

4. In combination with a device according to claim 1, an exhauster in the connection between the heat exchanger and condenser, a pump connected to discharge air into the distillation chamber at the bottom of the carbonizing section, and mechanical driving de- The material of course loses weight vice connecting the pump and aexhauster whereby the rate of air input will be maintained 1n predetermined relation to the rate of gas circulation.

5. In combination with a device according to claim 1, a stove connected in said second conduit to further heat gas flowing from the heat exchanger into the bottom of the carbonizing section. 6. In combination with a device according to claim 1, Valves in the first, second and third conduits to regulate the proportions of gas entering the different parts of the retort.

T. In apparatus for distilling carbonaceous material, a distillation chamber through wnich the material is passed including an evaporating section at the inlet end, a cooling section at the outlet end and a carbonizing section between the evaporating section and cooling section, an induction conduit leading to the outlet end of the'cooling section to deliver gas thereinto, a second induction conduit leading into the distillation chamber at a location intermediate the cooling section and carbonizing section, a third induction conduit leading into the distillation chamber at a location intermediate the carbonizing section and the evaporating section, and a fourth conduit leading from the distillation chamber at the inlet end of the evaporating section and means to transfer gas from said fourth conduit to said first, second and third conduits. I

8. In combination with a device according to claim 7, ,means connected to the fourth conduit for condensing volatiles out of gas received from the fourth conduit and for reheating the gas, and connection between said means vfor delivering reheated gas into the first, second and third conduits.

9. In combination with a device according to claim 7, pipes leading to the distillation chamber at a location between the cooling section and the carbonizing section to respectively deliver air and liquid hydrocarbon into the distillation chamber.

10. In combination with a device according to claim 1, a stove connected in said second conduit to further heat gas flowing from the heat exchanger into the bottom of the carhonizing section, a pipe to lead reheated gas flowing from the exchanger into the combustion chamber of said stove for use as fuel, and a flue leading from the stove to discharge products of combustion in the stove into the second conduit.

In witness whereof, I have hereunto set my hand. 7

FREDERICK T. SNYDER. 

